JPH0652217U - Dual beam antenna - Google Patents

Abstract

(57) [Summary] [Purpose] Two LNBs at the target position with respect to the fixed arm.
In the dual beam antenna for satellite broadcasting reception having the above, there is provided a dual beam antenna polarization angle adjusting mechanism capable of adjusting the polarization angle of the LNB and adjusting the inclination of the two LNBs with respect to the horizontal in a single operation. [Structure] Two LNBs 2-A and 2-B are connected so as to have an angle difference equal to the difference between the polarization angles of the receiving satellites,
At the time of installation, the position of the lower LNB2-B is fixed, and the polarization of the LNB2-B is adjusted by rotating the LNB2-B.
The position and polarization angle of NB2-A can be uniquely adjusted.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dual beam antenna for satellite broadcasting and satellite communication receiving equipment.

[0002]

[Prior art]

 Conventionally, a dedicated receiving antenna is used to receive radio waves from a communication satellite (hereinafter referred to as CS). In Japan, a plurality of CSs have been or will be launched into the geostationary satellite orbit at 4 degree intervals in the southeast direction. By using an antenna called a dual beam antenna, the radio waves from two adjacent CSs can be installed in a small installation space. Can be received at the same time. An example of the dual beam antenna is disclosed in Japanese Utility Model Laid-Open No. 3-107810. A conventional example of the dual beam antenna will be described below with reference to the drawings.

FIG. 4 shows a configuration of a conventional dual beam antenna. In FIG. 4, 1 is an offset type parabolic reflector, 2-A and 2-B are converters that receive radio waves from CS and output an input signal to a tuner (hereinafter referred to as LNB), 3 is the parabolic reflector 1 and the LNBs 2-A and 2-B are fixed at predetermined positions. Of the two LNBs, the one on the left side facing the parabolic reflector 1 is called LNB2-A and the one on the right side is called LNB2-B. FIG. 5 shows a mounting structure example of the two LNBs 2-A and 2-B and the arm 3. In FIG. 5, reference numeral 54 is an LNB holder for attaching the LNB2-A and 2-B to the arm 3. The LNB holder 54 is composed of an LNB holding portion 55 that directly holds two LNBs and an arm attachment portion 56 that is attached to an arm, and is connected and fixed to each other by a fixing screw 57. The fixing screw 57 is located at the focal position of the parabolic reflector 1 and fixes the LNB2-A and LNB2-B to an arbitrary position that is symmetrical to the focal point along the circumference centered on the focal point of the parabolic reflector. Have a function.

FIG. 6 is a front view of a state in which the dual beam antenna of FIG. 5 is installed to be receivable.

Next, a method of installing a conventional antenna will be described. In this embodiment, both of the two CSs to be received are on the east side of the receiving point. When the dual beam antenna is installed, as shown in FIG. 6, the line connecting LNB2-A and LNB2-B in the holder 54 of FIG. 5LNB is inclined by a predetermined angle with respect to the horizontal. This angle is a value calculated or calculated from the position of the receiving CS and the antenna installation place. Next, the LNB2-B receives the west CS, and the direction of the parabolic reflector 1 is adjusted so that the received power of the LNB-2B is maximized. When the adjustment is completed, the parabolic reflector is oriented almost at the midpoint between the two receiving CSs.

Next, the operation of the dual beam antenna installed as described above will be described. In FIG. 6, the radio wave from the west CS arrives from the upper side and the left side as shown by the arrow 8 in the original radio wave arrival direction of the parabolic reflector 1, and the parabolic reflector 1 makes an arrow with respect to the focal point 12 of the parabolic reflector 1. It is reflected to the right and downward as shown by 9, and is focused on the position of LNB2-B. On the other hand, in FIG. 6, the electric wave from the east CS arrives from below and on the right side as shown by an arrow 10 with respect to the original electric wave arrival direction of the parabolic reflector 1, and is reflected by the parabolic reflector 1 to the focus 12 of the parabolic reflector 1. On the other hand, it is reflected to the left and upward as shown by the arrow 11, and is focused at the position of LNB2-A.

By configuring and installing the dual beam antenna as described above, one parabolic reflector can receive radio waves from two CSs.

[0008]

[Problems to be solved by the device]

 In the above configuration, the conventional dual beam antenna has the following problems. The electric field from the CS is a linearly polarized wave in which the radio wave vibrates in a fixed linear direction at right angles to the traveling direction. A plane parallel to the traveling direction and including a straight line in the vibration direction is called a polarization plane. The angle between the horizon or the vertical line and the plane of polarization is called the polarization angle. An LNB that can receive linearly polarized waves is used to receive this radio wave. Generally, such an LNB can receive only one linearly polarized wave. In reality, since the polarization angle differs depending on the receiving place, when the antenna is installed, the LNB is rotated in the direction of arrow 13 in FIG. 5 to adjust so that optimum reception is possible. In the conventional dual beam antenna, it is necessary to tilt the two LNBs in the direction of arrow 14 in FIG. 5 with respect to the horizontal and at the same time adjust the polarization angle at the same time, which makes the adjustment work extremely complicated.

In view of the above problems, the present invention intends to provide a dual beam antenna capable of eliminating the complexity of the adjustment work by mechanically relating the adjustment of the polarization angle to the inclination of the LNB. To do.

[0010]

[Means for Solving the Problems]

 In the dual beam antenna of the present invention, the relative position of the two LNBs on the lower side is fixed. The polarization angle of the LNB is adjusted by rotating the LNB itself as in the conventional example. However, the lower LNB and the other upper LNB are relatively fixed to rotate the fixed LNB. Thus, the position of the upper LNB rotates about the lower LNB as an axis. The two LNBs are fixed so that the angle between the receivable polarization directions of each LNB is equal to the difference between the polarization angles of the radio waves from the receiving satellites. The fixed-side LNB has an angle between the straight line connecting the two LNBs and its own receivable polarization direction. The angle between the straight line connecting the two satellites to be received and the polarization plane of the radio wave from the satellite to be received by itself. It is fixed to match the angle formed by.

[0011]

[Action]

 According to the dual beam antenna of the present invention, by adjusting the azimuth angle and elevation angle of the fixed side LNB and then adjusting the polarization angle of the fixed side LNB, the other upper side LNB is adjusted to the fixed side. Rotating about the LNB of, the slope of the straight line connecting the two LNBs becomes equal to the slope of the straight line connecting the two satellites, and at the same time, the receivable polarization direction of the upper LNB from the satellite receiving It matches the polarization angle of the radio wave. Therefore, the position adjustment and the polarization angle adjustment of the upper LNB are unnecessary.

[0012]

【Example】

 A dual beam antenna according to an embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows the structure of a dual beam antenna according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 is an offset parabolic reflector, 2-A and 2-B are converters (hereinafter referred to as LNB) that receive radio waves from CS and output an input signal to a tuner, and 3 are It is an arm that fixes the parabolic reflector 1 and the two LNBs at predetermined positions. Of the two LNBs, the one on the left side of the parabolic reflector 1 is called LNB2-A and the one on the right side is called LNB2-B. Fig. 3 shows the polarization angles θa and θb of LNB2-A and LNB2-B, and the straight line connecting the two LNBs with respect to the horizon, in a state where the same dual beam antenna as the conventional example shown in Fig. 4 is installed so that it can be received in various parts of Japan. FIG. 6 is a diagram showing changes in the tilt angle θ of FIG. In FIG. 3, the polarization angles θa and θb are angles based on a straight line connecting two LNBs. Figure 3 can be calculated or calculated. As shown in FIG. 3, the polarization angles θa and θb with respect to the straight line connecting the two LNBs are constant regardless of the inclination θ of the LNB. Figure 2 shows an LNB mounting structure that incorporates these conditions. The two LNBs are connected by a metal fitting 6. The metal fitting 6 shown in this example can be divided into 6a and 6b, and is fastened with a screw 17 so as to fix the LNB2-A and 2-B at an arbitrary rotation angle. The LNB2-A is fixed by the metal fitting 6 so that the line 15 formed by the receivable polarization direction is inclined by the angle θa in FIG. 3 with respect to the line connecting the two LNBs. Similarly, the LNB2-B is mounted so that the straight line 16 formed by the polarization direction that can be received by the metal fitting 6 is inclined by the angle θb in FIG. 3 with respect to the straight line connecting the LNBs. The metal fitting 5 is fitted and fixed to the arm 3 and holds the LNB2-B in the same structure as the metal fitting 6. By loosening the screw 18 in the fitting 5, the LNB2-B can be rotated in the direction of the arrow 13. Next, the antenna adjustment method in this embodiment will be described. First, the elevation angle and azimuth angle of the antenna are adjusted so that the LNB2-B can receive the radio waves of the satellite on the east side. After adjusting the elevation angle and the azimuth angle, loosen the screw 18 of the metal fitting 5 and rotate the LNB2-B in the direction of arrow 13 to adjust the polarization angle. At this time, the LNB2-A rotates in the direction of arrow 14 around the LNB2-B as an axis through the metal fitting 6 to which the LNB2-B is fixed. Since the LNB B2-A and B hold the angle relationship of FIG. 3 by the metal fitting 6, the inclination of the straight line connecting the LNB2-A and 2-B can be adjusted by optimally adjusting the polarization angle of the LNB2-B. And the inclination of the straight line connecting the satellites to be received coincides with each other, and the polarization direction that can be received by the LNB2-A and the polarization angle of the radio wave from the east satellite coincide with each other.

By configuring the dual beam antenna as in the present embodiment as described above, the inclination of the straight line connecting the two LNBs and the other can be adjusted only by adjusting the elevation angle, the azimuth angle of the antenna, and the polarization angle of the LNB2-B. The polarization angle adjustment of LNB2-A can be simplified.

[0016]

[Effect of device]

 As described above, according to the present invention, since the adjustment process of the dual beam antenna can be performed only by adjusting the elevation angle, the azimuth angle of the antenna, and the polarization angle of one LNB, the adjustment of the dual beam antenna can be performed very easily.

[Brief description of drawings]

FIG. 1 is a perspective view showing a structure of a dual beam antenna according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view of an LNB mounting portion of the dual beam antenna of FIG.

FIG. 3 is a diagram showing the correlation between the receiving location of the dual beam antenna of the present invention and the LNB setting position.

FIG. 4 is a perspective view showing a configuration of a conventional dual beam antenna.

FIG. 5 is an enlarged perspective view of an LNB mounting portion of a conventional dual beam antenna.

6 is a front view of the dual beam antenna of FIG.

[Explanation of symbols]

 1 Parabolic reflector 2-A, 2-B LNB 3 Arm 4 Holder 5,6 Metal fittings 8,9 Trajectory of radio wave from satellite on the west side 10, 11 Trajectory of radio wave from satellite on the east side 12 Focus position of parabolic reflector 13 LNB rotation direction 14 Holder, metal fitting rotation direction 15, 16 LNB receivable polarization direction 17, 18 Metal fitting fixing screw

Claims (1)

[Scope of utility model registration request] 1. A dual beam antenna for satellite reception comprising a parabolic reflector, two converters, and an arm for holding the converters, wherein each of the two converters is centered on the axis of the converter itself. The dual beam antenna is characterized in that each of them is rotatably held and the other converter is rotatably held with the converter on the reference side as an axis to adjust the polarization angle.